Relation between insulin and aortic stiffness: A population-based study

Recent studies have suggested that a high pulse wave velocity (PWV), a measure of aortic stiffness, may be a stronger risk factor for cardiovascular disease (CVD) than a high blood pressure (BP). The relation between insulin, believed to play an important role in the development and clinical course of high BP, and PWV is not yet clear. Therefore, we decided to examine the relationship between insulin and PWV in a large population-based study. The study population consisted of a random sample of 1213 women and 1207 men (age range, 41-72 years) without a history of myocardial infarction or stroke. Fasting insulin was determined together with conventional risk factors for CVD. PWV was recorded transcutaneously by a mechanical electrical principle with one transducer positioned over the left common carotid artery, and another over the left femoral artery. In univariate analysis, insulin was highly significantly related to PWV (standardized regression coefficient: 0.0669 ± 0.0051; P<0.001). In multivariate analysis, controlling for all well-established predictors of PWV, such as age, systolic BP or mean BP and pulse pressure, sex, and heart rate, as well as controlling for conventional risk factors for CVD and use of BP-lowering drugs, the level of insulin remained a significant predictor of PWV (standardized regression coefficient: 0.0122 ± 0.0048; P = 0.012). In conclusion, the present study found that a higher insulin level was related to a higher PWV. This indicates that hyperinsulinaemia may affect BP and risk of CVD by increasing aortic stiffness.